• The Journal of Korean Academy of Prosthodontics
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• v.38 no.1
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• pp.50-58
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• 2000

The purpose of this study was to investigate the causes of food impaction and to explore solutions as well. For this study, 39 patients with food impaction were selected. 77 contact areas in these patients were investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone loss, proximal caries, marginal ridge distance and occlusal relationships. The results were as follows ; 1. Teeth without distal support were found to be the most frequent site of food impaction (41.6%). Food impaction was found to be more frequent in the upper teeth (65.2%) than the lower teeth (33.8%). 2. Food impaction was found in tight contact cases (71.4%). Alveolar bone loss was not found in the early stage of food impaction (83.1%) 3. The distance between the marginal ridges of food impaction sites (mean=0.48mm) was short-er than that of the control group. (mean=0.77mm) (p<0.001) 4. In 18.2% of the cases, proximal carries were found at the food impaction site. 5. Food impaction affected patient's occlusion with the following frequencies, cusp to marginal ridge relationship (72.7%), cusp to fossa relationship (3.9%) and stepped relationship (23.4%).

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.47-53
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• 2024

Interproximal contact loss (ICL) is the most frequent complication in partially edentulous patients treated with implant-supported prostheses. However, in most cases, ICL occurs between the implant prosthesis and the natural tooth due to the movement of the natural tooth. There are several causes of ICL that occur between an implant prosthesis and a natural tooth. There are only a few reported cases of ICL occurring between implant prostheses, and explaining the causes of ICL between implant prostheses and natural teeth is challenging. This clinical report describes cases of ICL between implant prostheses and discusses its causes and countermeasures.

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.284-289
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• 2002

Background : The purpose of the present study was to evaluate the direct and indirect composite restorations which had been placed for 1 year Methods : The composite restorations which had been placed between 1999. Mar and 1999, Dec was evaluated after 1 year For direct restorations. Spectrum (Dentsply, USA) and Z100 (3M, USA) were used in the anterior teeth and Surefil (Dentsply, USA) were used. For class V restorations of anterior and posterior teeth. Spectrum was used. For indirect restorations, Targis/Vectris system (Vivadent/Ivoclar, Liechtenstein) was used 2 examiners evaluated marginal quality, proximal contact. discoloration, presence of 2$^{nd}$ caries, loss of filling and hypersensitivity of restorations. The restorations was clinically evaluated by modified methods based on USPHS. Results : 60 teeth were evaluated. 59 were clinically acceptable and 1 restoration which was placed in class v cavity in the posterior tooth was fallen out. In most cases, the restorations were clinically accept-able. For restorations which had been directly placed in the class II cavities, loose proximal contact was indicated as the main complaints. Conclusions : Most of Anterior and posterior restorations which bad been directly or indirectly placed for 1 year were clinically acceptable. For posterior teeth, loose proximal contact was indicated as the main problem in the directly placed Class II restorations. Long term clinical study is needed.

• Journal of the korean academy of Pediatric Dentistry
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• v.3 no.1
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• pp.7-11
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• 1976

The author measured the degree of development and the eruption pattern of first permanent molars with orthopantomography in 553 Korean children(male; 302, female; 251) from 4 to 9 years old. The orthopantomographs were obtained from dept. of pedodontics, college of dentistry, Seoul National University. The results of the studies were as follows: 1. Upper first permanent molars were erupted with distal inclination of about 30 degrees in the early stage and they gradually moved in the mesial direction by bodily movement of the tooth to be in contact with the disto-proximal surface of primary secondary molars in the late stage. 2. Lower first permanent molars were erupted with mesial inclination in the early stage and moved mesially by tipping movement of the tooth to be in contact with the disto proximal surface of the second primary molars in the late stage. 3. The eruptive forces were considered to be main etiologic factors of space closure after the premature loss of primary molars.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.9-17
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• 2022

Purpose: The purpose of this study is to investigate how open contacts impact the natural teeth and dental implant prostheses. Materials and Methods: Following criteria were used to select 20 implant crowns with open proximal contacts as the experimental group (Group A): the restorations were delivered in Chosun University Dental Hospital between 2008 and 2018, the restorations are in the posterior region, opposing teeth are fixed dental prostheses, neighboring teeth are sound natural teeth, the patient had been on the maintenance program for at least 3 years. Another 20 implant crowns with closed proximal contacts were selected as the control group (Group B) using the same criteria. Between the two groups, dental caries and food impaction of the neighboring natural teeth and marginal bone-loss of the implants were compared and evaluated. Results: There was no statistically significant difference between Group A and Group B in the occurrence rates of dental caries, food impaction, and marginal bone-loss. The amount of marginal bone-loss, however, revealed statistically significant differences between the two groups, with Group A showing 0.80 ± 0.39 mm loss and Group B showing 1.1 ± 0.43 mm loss. Conclusion: Implant prostheses with open contacts could be clinically considered in select cases as such restorations revealed no harmful effects on neighboring teeth and implant restorations within the perimeters of this study.

• The Journal of the Korean dental association
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• v.54 no.3
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• pp.198-205
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• 2016

The purpose of this paper was to investigate the significance of splinted and non-splinted implant-supported restorations with an internal connection for multiple consecutively missing teeth. Upon examination of the effects of fixture-abutment connection, the distribution of occlusal load was favorable in splinted implant-prosthesis with an external connection, but effect of strain distribution was not significant in splinted implant-prosthesis with an internal connection. In splinted implant-prostheses for short implants, strain distribution was not affected by the method of retention. For cement-retained prostheses, the effect of strain distribution due to splinting was not significant. In clinical studies, non-splinted prostheses with an internal connection for multiple consecutively missing teeth showed high survival rate, mild marginal bone loss, and stable periodontal condition. However, failure to achieve optimal proximal contact between single-unit prostheses may lead to food impaction, and veneer fracture may be inevitable when the framework provides inadequate support in the proximal region. In conclusion, splinted implant-prosthesis is not an indication in all cases, and clinical consideration of its use should be based on the patient's oral condition, such as location and number of implants, formation of proximal contact, canine guidance, existence of parafunctional habit, and oral hygiene, when multiple consecutively missing teeth are replaced by internal connection type implant.

• The Journal of Advanced Prosthodontics
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• v.11 no.2
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• pp.88-94
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• 2019

PURPOSE. This study was conducted to investigate patterns of adjacent tooth displacement in the posterior implant with interproximal contact loss (ICL) by 3-D digital superimposition method. MATERIALS AND METHODS. Posterior partially edentulous patients, restored with implant fixed partial prostheses before 2011 and suffered from food impaction of ICL between 2009 and 2011, were included. Two dental casts, at the time of delivery and at the time of food impaction in a same patient, was converted into 3-D digital models through scanning and superimposition was performed to assess chronologic changes of the dentition. Directions of tooth displacement were evaluated and the amount of ICL was calculated. Correlations between the amount of ICL and elapsed time, or between the amount of ICL and age after function, were assessed at a significance level of P<.05. RESULTS. A total number of 13 patients (8 males, 5 females) with a mean age of $65.76{\pm}9.94years$ and 17 areas (4 maxillae, 13 mandibles) were included in this retrospective study. Teeth adjacent to the implant restoration showed complex displacements but characteristic tendency according to the location of the arch. The mean amount of ICL was $0.33{\pm}0.14mm$. Elapsed time from function to ICL was $61.47{\pm}31.27months$. There were no significant differences between the amount of ICL and elapsed time, or age (P>.05). CONCLUSION. Natural teeth showed various directional movements to result in occlusal change in the arch. The 3-D superimposition of chronologic digital models was a helpful method to analyze the changes of dentition and individual tooth displacement adjacent to implant restoration.

• Journal of Periodontal and Implant Science
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• v.31 no.3
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• pp.625-631
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• 2001

The anatomic structure around interproximal area plays an important role not only in the natural teeth, but also in the implant. The loss of papilla can lead to cosmetic deformity, phonetic problem, food impaction on the anterior dentition, and masticatory problem, food impaction and proximal caries on the posterior dentition. The purpose of this study was to evaluate the relationship between interdental papilla existence and distance from contact point to alveolar crest in Korean posteior dentition. 45 Korean adult patients(31males, 14 females) participated in this study. Measurements were carreid out total 126 interproximal areas, 18 first premolar, 31 second premolar, 40 first molar, and 37 second molar areas. Papilla index was recorded as suggested by Jemt. Distance between contact point and alveolar crest measrued by Florida $probe^{R}$, after flap elevation. Each distance was measured 10 times by every 0.1mm unit. The results showed that the mean Papilla index 1.37 and mean distance between contact point and alveolar crest was 7.44mm. The correlation between the Papilla index and distance was high negative correlation(Pearson correlation=-0.47), and it was statistically significant(P=0.000) When the distance between contact point and alveolar crest was 5mm, the loss of papilla was appeared almost in half cases. When the distance was 6mm, the papilla loss was present 95%, when 7mm, the papilla loss was 100%.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.277-295
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• 1997

After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.25-31
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• 2012

Purpose: The clinical and radiographic outcomes of the internal fixation, which were executed on patients over the age of 65 with proximal humerus fracture by using a polyaxial angular stable locking compression plate (Non-Contact-Bridging proximal humerus plate, Zimmer, Switzerland, NCB), were evaluated. Materials and Methods: Thirty two patients over the age of 65 among the proximal humerus fracture treated with NCB plate, between August 2007 and January 2011, were chosen as the subjects. The average age of patients was 71 years, and the average postoperative follow-up period was 11.5 months. The fractures included 14 two-part and 18 three-part fractures. The clinical results were evaluated, using the visual analog scale (VAS) score and the Constant score. The radiological results were evaluated by time to union and Paavolainen method, which measures the neck shaft angle. Results: At the last follow-up examination, the mean VAS score was 3 points and the mean Constant score was 64.5 points, with bone union achieved after the average of 16.2 weeks following the surgery in all the cases. The mean neck shaft angle was 125.9 and 24 cases had good results, while 8 cases had fair results by Paavolainen method, at the last follow-up. There were 1 case of delayed union and cerclage wire failure, and 3 cases of subacromial impingement. There were no complications, such as loss of reduction, nonunion, screw loosening, or avascular necrosis of the humeral head. Conclusion: Internal fixation, using a NCB plate, was considered to be an effective surgical method in treating proximal humerus fracture in the elderly patients, on whom the fixation of the fracture and maintenance of reduction are difficult.